Means por regulating alternating current



Oct. 9,1928.

c. E. STRYKER MEANS FOR REGULATING ALTERNATING CURRENT Filed Jan. :51,1927 5 I 1 gig J Patented Oct. 9, 1928.

UNITED STATES PATENT OFFICE.

' CLINTON E. STRYKER, NORTH CHICAGO, ILLINOIS, ASSIGNOR TO FANSTEELPROD- UCTS COMPANY, INC., 0]! NORTH CHICAGO, ILLINOIS, A CORPORATION OFNEW YORK.

IEANS FOR REGULATING ALTERNATING CURRENT.

Application filed January 31, 1927. Serial No. 165,018.

My invention relates to means for regulating alternating current bymeans of a chokering. More particularly this invention relates toregulating high amperage, low voltage current for use in a sinteringfurnace,

using 10,000 to 12,000 amperes at about 12 volts. The heating currentfor use in sintering furnaces has been controlled by regulating thecurrent in the primary circuit, such ourrent regulators necessarilybeing subjected to high voltages. The object of this invention is toobviate this difficulty by providing a simple current regulator with arange of 2,000 to 10,000 amperesrin the secondary circuit.

A further object of the invention is to do away With the necessity ofexpensive insulation required in the choke coils now used and to designan impedance that will not cause a repelling force in the choke coil.

, A further object of this invention is to improve the process ofregulating low voltage,

high amperage currents by means of a special type of choke-ring to causeimpedance.

A further object of this invention is to provide'a choke-ring. suitablefor current regulation.

' Other objects will be apparent as description of the inventionproceeds.

A preferred modification of my invention is illustrated in theaccompanying drawings, in which similar reference characters refer tosimilar parts throughout.

Figure 1 is a diagrammatic drawing of the wiring system, showing theposition of the choke-ring.

Figure 2 is a vertical section of the chokering.

Referring to Figure 1, alternating current of high voltage is suppliedfrom mains 1 and 2, and is conducted by wires 3 to the primary coil 4.Element 5 represents the core of the transformer, and coil 6 representsthe secondary coil which is connected by conductors 7 and 8 to bindingposts 9 and 10 of an elec .tric furnace 11.

Between the secondary coil 6 and binding post 10 a chokering 12 isplaced around conductor 8. A preferred embodiment of the choke-ring isshown in Figure 2.

On a base 13, preferably of wood, are mounted bronze track ways 14,which support rollers 15 turning on axles 16, mounted in brackets 18.fixed to a U shaped laminated iron block 17. This block is movable bymeans of a screw 18 running in a bracket 19, supported on base 13 bybolts 27. By turning a wheel 20 fixed to said screw 18, the U shapedblock 17 is moved toward a block 21, also formed of laminated iron andsupported by bracket 19, secured to the base 13 by bolts 27 The U shapedblock 17 is composed of two parallel portions 22 and 23, connected by anintegral upright portion 24. Its ends 25 are tapered toward the innerside. The parallel portions 22 and 23 are spaced so that when block 17is moved to the left, it will slide over block 21, thereby forming aring and completing the magnetic circuit.

It is noted that by means of the fine regulation, any suitable air gapor effective cross sectional area may be provided whereby the magneticcircuit may be varied at will. lVithin this choke-ring is a conductor 8,which may be of any suitable material adapted to carry a current of10,000 to 12,000 amperes. IVhile I have shown a preferred embodiment ofmy invention, I desire it to be understood that I do not limit myself tothe precise details shown and described. The elements of the inventionare to be defined by the following claims.

I claim 1. In a choke-ring for varying the impedance in a secondarycircuit, a U-shaped, laminated iron block formed by spaced horizontalbars with a connecting bar integral with one end of each, taperedportions at the other end of each horizontal bar, a laminated iron blockadapted to fit between the horizontal bars, means for supporting thisblock and the U-shaped block, and means for moving one relative to theother whereby the first may be spaced from the second, adjacent itstapered portions, or entirely between its horizontal bars.

2. In a choke-ring for varying the impedance in a secondary circuit, aU-shaped block with tapered edges, a block adapted to fit between saidtapered edges but not in actual contact therewith. and means for movingone of these elements toward and away from the other whereby thereluctance of the magnetic field may be varied.

In witness whereof, I hereunto subscribe my name this 28th day ofJanuary, 1927.

CLINTON E. STRYKER.

